The primary purpose of the phase Ib part of this study is to determine the maximum tolerated dose(s) (MTD(s)) and/or recommended phase II dose (RP2D) of LEE011 + everolimus + exemestane in patients with ER+ Her2- advanced breast cancer. This part of the study will also assess safety, tolerability, and PK of the LEE011 + exemestane, LEE011 + everolimus + exemestane combinations.